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ARS Home » Pacific West Area » Pullman, Washington » WHGQ » Research » Research Project #434909

Research Project: Finding Solutions to Low Falling Number Wheat in Idaho

Location: Wheat Health, Genetics, and Quality Research

Project Number: 2090-21000-033-005-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jul 1, 2018
End Date: Jun 30, 2023

1. Investigate the genetic architecture of low falling numbers in wheat and specifically in spring wheat adapted to southern Idaho. Develop new wheat germplasm and populations segregating for response to falling number (Chen). a. Collaborate to share phenotypic data to develop selection models to improve falling number resistance in wheat cultivars targeted to the Pacific Northwest and specifically to Idaho. b. Collaborate to share germplasm resources to better define molecular markers associated with resistance to falling number, whether caused by late maturity alpha amylase or preharvest sprouting. 2. Develop white wheat genotypes containing an alpha amylase-fluorescent protein reporter constructs enabling the precise identification of late-maturity-alpha-amylase-affected grains for use in understanding the differences between LMA and preharvest sprouting. (FU) 3. Determine the association between winter wheat genotypes and fungicide applications and the risk of falling number in wheat cultivars (Marshall) using a mapping population derived from a susceptible parent (Yellowstone hard red winter wheat) and an advanced breeding line from the WSU breeding program.

Low falling numbers (FN) causes serious financial losses for U.S. farmers every year. Low FN can be caused by the starch degrading enzyme alpha-amylase and by other enzymes expressed during either the developmental defect called late maturity alpha-amylase (LMA) or preharvest sprouting (the germination of grain on the mother plant). 1. Develop new wheat germplasm with improved resistance to low FN, and spring and winter wheat mapping populations segregating for resistance to low FN. Mapping populations developed by the COOPERATOR and ARS will be shared under a MTA and owned by the Cooperators and ARS, respectively. The Cooperator and ARS will collaborate on phenotyping of LMA and provide collected data to the owner of the mapping populations. The COOPERATOR and ARS will conduct phenotypic and QTL analysis as well as selection tools in their owned materials, but shared with each other to to breed wheat cultivars with high resistance to problems with low FN. 2. Wheat will be transformed with transcriptional and translational fusions of the wheat TaAmy1 alpha-amylase gene fused to a fluorescent reporter gene (such as green and red fluorescent protein). The ARS and the COOPERATOR will collaborate to isolate a genomic clone of TaAmy1 including the promoter region based on knowledge of the barley homologue. The ARS will test wheat varieties that transform well to determine which may be LMA susceptible. The ARS will create the constructs for transformation. The COOPERATOR will use biolistics to transiently transform wheat aleurone to check the the constructs are expressed in response to GA and inhibited by ABA. The COOPERATOR will generate stable wheat transformants expressing the constructs using Agrobacterium tumefaciens-based transformation. The ARS will increase the seed and conduct tests to assay the expression of alpha-amylase in wheat aleurone. 3. Detect the association between wheat genotype, fungicide and susceptibility to low falling number in a winter wheat mapping population. The COOPERATOR will design and conduct replicated field trials of wheat cultivars in multiple locations in southern Idaho with a strobilurin fungicide application at late boot compared to a non-treated control. The COOPERATOR will examine the effects of LMA induction via strobilurin application in environments without likelihood of PHS-inducing conditions. The ARS will assay samples for falling number, and if needed will assay samples for PHS and LMA using half-grain assays. The COOPERATOR will use these data to provide information to farmers and researchers on the effects of nitrogen and fungicide treatments on falling number in wheat.